It always surprises me when someone asks why I love science. Of course, it's a valid question, but for me I wonder how anyone couldn't: to love science is to love being alive. How could I not be interested in the world? There's a whole universe to know – 13.82 billion years of it – and since most of us will only get about 71 years here, shouldn't we find joy in everything we discover?

Think about this: our brains have more connections than there are stars in the galaxy (that's 100 trillion neural connections to 100 thousand million stars). Every element in this solar system was formed in the death throes of stars, and every element in this universe was formed from early nuclei that developed threeminutes after the Big Bang. Everything is connected to everything else, in a completely physical, practical sense: this universe is a closed system with a finite amount of mass. Nothing is created or destroyed, only changed.

Looking at the world this way changes everything. We are each of us the product of 13.8 billion years of universal evolution, and 3.8 billion years of biological evolution on Earth. We have a common ancestor with every human, every animal, every blade of grass. I know that life can be wearying, and that it's easy to lose interest in – or forget to love – being alive in this world. But even simple questions or tiny discoveries can rekindle our wonder.

Think about the screen you're looking at. Your eyes are taking in the light of my words at a frame rate of 14 images per second, each upside down like a camera obscura – but your brain flips things back around for you. Can you feel your heartbeat? Today alone your heart will pump some 7,200 liters of blood through your body. You've been able to hear since 20 weeks before you were born. What can you hear now? How do those vibrations travel through the air as sound? What about the time you're moving through right now, the Earth's magnetic field shielding you from cosmic rays that could rip through DNA, your fingernails growing at the same rate continents move, the sunlight that was formed in our star's core 200,000 years ago when the human race began?

The same forces that hold your nuclei together and pull your feet toward the ground are the forces orchestrating the nature of reality. The universe is 92 billion light years across and growing every second. You breathe what trees exhale. No one knows why you dream.

Life is hard, but not all of it. There is so much discover, so much to ask. Complexity is all around us. So yes, I love science – because I love that I get to be alive in this universe, and that I can be a part of this young species that is, as Carl Sagan said, a way for the cosmos to know itself.